In power semiconductor devices, bases and sources must be terminated. For example, JP-A 2009-505434 discloses an implantation of a source dopant using a mask to selectively form a source region in an element region. To determine the source region, it is necessary to fabricate a mask by lithography and etching. The source region is not formed in the termination region. Hence, the element region structure and the termination region structure cannot be formed in the same process, leading to a problem of an increase in number of processes and thus cost.